This invention relates to elastomeric springs and, more particularly, to tubular, composite springs.
Tubular, composite springs are made up of a tubular elastomeric body and a coil spring embedded in the body to reinforce it against lateral buckling. In many practical applications, it is desirable to mount such springs in locations in which they are subjected to axial compression loads, which may or may not be applied axially. While it is important to secure the ends of the spring to the sprung and unsprung mass associated with the particular application, it is particularly important to be able to maintain positive securement and positioning of the spring ends where bending or twisting forces are applied to the spring on account of such off-axis load.. This is a common requirement in many vehicular applications, since the location and orientation of the spring often are determined by the geometry of the suspension, the location of the shock absorbers and other factors.
In many vehicular applications, a further requirement is that one or both ends of the composite spring be mountable by the same spring seat as that used to mount the ends of a coil spring. This seat typically includes a protruding central portion which projects axially into one end of the coil spring, forming a circular shoulder which engages the inner face of, and positions, the outermost coil. When used with a composite spring, however, this seat tends to be unsatisfactory because the end of the spring, being formed of elastomer, is deformable in the region of contact with the seat. Consequently, external containment or clamping devices must be used to obtain the positive securement and positioning described above. In many practical vehicular applications, however, the suspension geometry does not provide sufficient space adjacent to the spring for such devices.